Ventilation unit



FIG. 1 is a front and right side perspective view of a ventilation unit,showing my new design;

FIG. 2 is a right side elevation view thereof, the opposite side being amirror image of that shown;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a top plan thereof; and,

FIG. 6 is a bottom plan view thereof.

The ornamental design for a ventilation unit, as shown and described.